Update global nav HTML
Tiny MVC for #972 (closed) , nuff said
When making use of the new level 4 and level 5 nested-documentation functionality !1625 (merged), expanding and collapsing a level three item can hide other level three items, instead of limiting itself to it's own level 4 and level 5.
Looks like I missed a div inside layouts/global_nav.html and I didn't notice because the nanoc syntax makes the file very hard to lint unless you're eyeballing it and I am not quite that good
I have however updated the indentation / commenting of the file to make this easier for future now to reduce technical debt and added in the missing div should we should be okay here
I've left the updated YAML file in this merge for your testing on the review app, so we can revert that file when we want to merge this one
Also note the level five item isn't quite styled the same color as the rest.
That was done on purpose but I have changed it to match the rest